Acceleration sensor

Abstract

An acceleration sensor, including a base; anchor point; an inner side supporting unit, a middle part of which is fixed to the base through the anchor point, a first seesaw unit elastically connected to an outer side of a first end of the inner side supporting unit; a second seesaw unit elastically connected to an outer side of a second end of the inner side supporting unit; and an out-of-plane displacement detection unit. Each of the first seesaw unit and the second seesaw unit is symmetrically distributed about a symmetry axis of the acceleration sensor. The first seesaw unit includes two first seesaw structures at two sides of the symmetry axis and the second seesaw unit includes two second seesaw structures at two sides of the symmetry axis. An influence of Y-axis angular acceleration on the acceleration sensor is greatly reduced and a cross inhibition ratio thereof is improved.

What is claimed is: 
     
         1 . An acceleration sensor, comprising:
 a base;   an anchor point;   an inner side supporting unit comprising a first end and a second end, a middle part of the inner side supporting unit being fixed to the base through the anchor point;   a first seesaw unit and a second seesaw unit; and   an out-of-plane displacement detection unit provided at each of the first seesaw unit and the second seesaw unit,   wherein the first seesaw unit is elastically connected to an outer side of the first end of the inner side supporting unit, the second seesaw unit is elastically connected to an outer side of the second end of the inner side supporting unit; the first seesaw unit and the second seesaw unit are opposite to each other, and each of the first seesaw unit and the second seesaw unit is symmetrically distributed about a symmetry axis of the acceleration sensor; the first seesaw unit comprises two first seesaw structures arranged at two sides of the symmetry axis, and the two first seesaw structures both rotate about a first rotation axis; the second seesaw unit comprises two second seesaw structures arranged at two sides of the symmetry axis, and the two second seesaw structures both rotate about a second rotation axis; the first rotation axis and the second rotation axis are arranged in parallel, and the symmetry axis is perpendicular to the first rotation axis or the second rotation axis.   
     
     
         2 . The acceleration sensor as described in  claim 1 , wherein a first groove is provided at an outer side of the first seesaw unit, a second groove is provided at an inner side of the second seesaw unit, a part of the first seesaw unit is embedded in the second groove, and a part of the second seesaw unit is embedded in the first groove to form an embedded structure, which is located between the first rotation axis and the second rotation axis. 
     
     
         3 . The acceleration sensor as described in  claim 2 , wherein further comprising a first detection weight and a second detection weight;
 wherein each first seesaw structure comprises a first rotating sub-portion and a second rotating sub-portion, the first rotating sub-portion and the second rotating sub-portion are located at two opposite sides of the first rotation axis, and the first groove is provided at an outer side of the second rotating sub-portion; each second seesaw structure comprises a third rotating sub-portion and a fourth rotating sub-portion, the third rotating sub-portion and the fourth rotating sub-portion are located at two opposite sides of the second rotation axis, and the second groove is provided at an inner side of the third rotating sub-portion;   wherein the first detection weight is located at the first rotating sub-portion, the second detection weight is located at the fourth rotating sub-portion, and the first detection weight and the second detection weight are symmetrically arranged.   
     
     
         4 . The acceleration sensor as described in  claim 2 , further comprising a coupling beam,
 wherein the coupling beam extends in a direction perpendicular to the symmetry axis, an end of the coupling beam is connected to the second rotating sub-portion, and another end of the coupling beam is connected to the third rotating sub-portion.   
     
     
         5 . The acceleration sensor as described in  claim 1 , further comprising a first elastic member and a second elastic member,
 wherein the first seesaw unit is connected to the first end of the inner side supporting unit through the first elastic member; and the second seesaw unit is connected to the second end of the inner side supporting unit through the second elastic member; and   wherein the first elastic member is close to the first rotation axis and extends in a direction parallel to the first rotation axis; and the second elastic member is close to the second rotation axis and extends in a direction parallel to the second rotation axis.   
     
     
         6 . The acceleration sensor as described in  claim 1 , wherein the out-of-plane displacement detection unit is located at a region of the first seesaw unit away from the first rotation axis; and
 the out-of-plane displacement detection unit is located at a region of the second seesaw unit away from the second rotation axis.   
     
     
         7 . The acceleration sensor as described in  claim 1 , wherein the two inner side supporting units are symmetrically distributed about the symmetry axis; and each of the two inner side supporting units is fixed to the base through a respective anchor point located at an inner side of the inner side supporting unit. 
     
     
         8 . The acceleration sensor as described in  claim 7 , further comprising an X-axis acceleration detection structure configured to detect acceleration along an X-axis direction,
 wherein the X-axis acceleration detection structure is located between the two inner side supporting units, and the X-axis acceleration detection structure is symmetrically distributed about the symmetry axis.   
     
     
         9 . The acceleration sensor as described in  claim 7 , further comprising a Y-axis acceleration detection structure configured to detect acceleration along a Y-axis direction,
 wherein the Y-axis acceleration detection structure is located between the two inner side supporting units, and the Y-axis acceleration detection structure is symmetrically distributed about the symmetry axis.   
     
     
         10 . The acceleration sensor as described in  claim 7 , further comprising an X-axis acceleration detection structure and a Y-axis acceleration detection structure,
 wherein the X-axis acceleration detection structure is configured to detect acceleration along an X-axis direction; and the Y-axis acceleration detection structure is configured to detect acceleration along a Y-axis direction; and   wherein the X-axis acceleration detection structure and the Y-axis acceleration detection structure are both located between the two inner side supporting units, and the X-axis acceleration detection structure and the Y-axis acceleration detection structure are located at two opposite sides of the anchor point.   
     
     
         11 . The acceleration sensor as described in  claim 1 , wherein the two inner side supporting units are symmetrically distributed about the symmetry axis, and middle parts of the two inner side supporting units are connected to each other at a position of one anchor point located at a junction between the two inner side supporting units. 
     
     
         12 . The acceleration sensor as described in  claim 11 , further comprising an X-axis acceleration detection structure configured to detect acceleration along an X-axis direction,
 wherein the X-axis acceleration detection structure is located between the two inner side supporting units, and the X-axis acceleration detection structure is symmetrically distributed about the symmetry axis.   
     
     
         13 . The acceleration sensor as described in  claim 11 , further comprising a Y-axis acceleration detection structure configured to detect acceleration along a Y-axis direction,
 wherein the Y-axis acceleration detection structure is located between the two inner side supporting units, and the Y-axis acceleration detection structure is symmetrically distributed about the symmetry axis.   
     
     
         14 . The acceleration sensor as described in  claim 11 , further comprising an X-axis acceleration detection structure and a Y-axis acceleration detection structure,
 wherein the X-axis acceleration detection structure is configured to detect acceleration along an X-axis direction; and the Y-axis acceleration detection structure is configured to detect acceleration along a Y-axis direction; and   wherein the X-axis acceleration detection structure and the Y-axis acceleration detection structure are both located between the two inner side supporting units, and the X-axis acceleration detection structure and the Y-axis acceleration detection structure are located at two opposite sides of the anchor point.